This project is designed to further advance a systematic investigation of the role of Social Support in the general Stressor-Illness model. The project has conducted a pre-test and collected two waves of daa (at a one year interval) from a representative sample of adults (N=1100) in the Albany - Troy - Schenectady area of New York. The basic objective of the proposed study is to test alternative hypotheses regarding the inter-relationships among stressors, social support and illness. The two-wave panel data in hand will be used to 1) construct causal models relating stressors and social support to illness (primarily depressed mood), 2) to examine other empirical indicators (measured variables) for the concepts in the basic causal model, and 3) to specify these causal models in terms of other social and personality variables which have been found meaningful in previous analyses (e.g., age, sex, marital status and self-esteem). We will use the structural equation modelling technique to incroporate both unobserved and measured variables, to estimate equation and measurement errors and to identify any potential reciprocal effects among the unobserved variables (i.e., stressors, social support and illness). We will also utilize other nonlinear, tabular analytic techniques to uncover other patterns of relationships. This effort represents an advanced step in examining the causal role played by social support in the epidemiology of illness. The long-term objective, including a potential third-wave survey, is to firmly establish a rigorous stressor-social support-illness model, specified for each meaningful segment of the age structure, sex role, marital status and cohort-period variations.